Partial protection of the gastric toxicity of regional 5-fluorouracil infusion by thymidine and cimetidine.

Gastric ulceration resulted from regional (infusion) chemotherapy when high doses of 5-fluorouracil were accidently infused into the stomach during hepatic artery infusions. A method for reproduction of those ulcers was established by gastric artery infusions. A trial to protect against such development with thymidine produced only partial protection. Measurement of gastric acid output in animals receiving one dose of 5-fluorouracil showed no change in basal acid secretion but a significant decrease in histamine-stimulated output. Partial protection from ulcer development was also accomplished with cimetidine alone.